Pencil sharpener



Feb. 27, 1951 H. M. MGCLURE PENCIL SHARPENER Filed Aug. 12, 1947 INVENTOR HUGH M. McCLURE 7 IBM/9w HIS ATTORNEY Patented Feb. 27, 1951 UNITED STATES PATENT OFFICE PENCIL SHARPENER Hugh M. McClure, Chicago, Ill. Application August 12, 1947, Serial No. 768,129

3 Claims. (Cl. 120-89) This invention relates to pencil sharpeners, and has for an object the provision of new and improved devices of this type.

More particularly the invention has for an object the provision of sharpening devices for shaping and pointing the leads of drafting pencils, or the like, wherein a needle or chisel point may be imparted to the lead without the exercise of skill or attention upon the part of the operator.

Another object .ofthe invention is to provide in a device ofthis character, abrasive means arranged in such formation as to include spirally curved surfaces which shape without tendency to fracture a pencil point to a configuration ideal for drafting purposes.

Still another object of the invention is to provide a device having elongated trough means,

substantially V-shaped in cross section, and wherein the walls defining the trough means diverge laterally and longitudinally from one end to the other, and are so contoured as to impart longitudinally extending opposed spiral curves to the said walls.

A still further object of the invention is to provide a holder for abrasive means, so constructed that application of the abrasive means thereto positions and shapes the abrasive means in a fashion to produce the characteristic operation of the device.

Still another object of the invention is to provide a holder wherein abrasive means employed in connection therewith, are readily attachable and replaceable, and wherein properties of the abrasive means are utilized for retaining the same in operative position.

Other and further objects of the invention will comprises an elongated holder I0, preferably made of stainless steel, although the holder might be constructed of any other suitable material, such as plastic. The holder I is of elongated trough-like form, and in cross section is substantially acutely V-shaped, having a rounded apex portion II, and side walls I2 and I3. From adjacent one end of the holder, indicated at It, the side walls I2 and I3 diverge laterally and longitudinally at uniformly constantly changing angles, starting at the substantially parallel walls best shown in Figure 4, and gradually increasing, as shown in Figures and 6, to a point adjacent the opposite end I5 of the holder It." In addition to their lateral and longitudinal divergence,

each of the walls I2 and I3 is concavo-convex, being gently curved laterally and longitudinally to produce a substantially spirally or helically appear from the specification and claims, and

from the accompanying drawings, in which: I

Figure 1 is a perspective view illustrating the manner of use of an embodiment of the invention,

Figure 2 is a side elevational view of said embodiment,

Figure 3 is a top plan view of the illustrated embodiment,

Figure 4 is a transverse vertical sectional view, corresponding substantially to the line 44 of Figure 2,

Figure 5 is a view similar to Figure 4, and corresponding to the line 5-5 of Figure 2,

Figure 6 is a view similar to Figure 4, and corresponding to the line 6-6 of Figure 2.

Figure 7 is a perspective detailed view of an abrasive member employed in connection with the invention, while Figure 8 shows a different embodiment of the invention. i As shown in Figures 1 through 7 of the drawthe illustrated embodiment of the invention curved contour I6 from one end M of the holder [0 to the other end I 5 of said holder.

The apex portion II, beyond the end portion I5, is provided with an extension I1, which is tilted from the apex portion II inwardly, as indicated at I8. The extension H is preferably triangular in shape when the holder Ill is viewed edgewise, with its attenuated portion I 9, connected to the apex portion II, and its broadened portion 20, extending outwardly from the end portion I5. The outer margins of the extension 11 are provided with upturned portions or flanges 2| and 22, these flanges being slightly tilted away from each other. An aperture 23 may be provided in the triangular extension I1, to provide means by which the holder l0 may be hung on a nail or the like.

Adapted for insertion into the holder I6, is a pair of abrasive strips or liners 24 and 25. These strips may be of any suitable kind, but preferably comprise cardboard strips of the type shown in Figures 1, 2, 3 and '7, ordinarily used for manicuring or filling the finger nails, and which are readily obtainable cheaply in the open market. The strips 24 and 25 are composed of relatively stiff but flexible cardboard, ,or similar material, and are provided upon their faces with an abrasive material indicated at 26. The strips 24 and 25 are obtainable in different breadths, thicknesses, and lengths. The breadth of the same in the present instance is not particularly important, so long as the strips are slightly broader than the walls l2 and I3. The strips [2 and I3, however, need to be, and are readily obtainable in, lengths somewhat greater than the length of the holder I9, exclusive of the extension l'l. They should also be of a thickness so that the combined thicknesses of two will fit snugly between the walls IZ and I3 at the end IA of the holder l0. These strips 24 and 25, when placed within the holder Ill, with the abrasive surfaces" 25 directed toward each other, and with one set of ends between the walls [2 and [3, adjacent the end M of the holder l0, lie flat along the interior surfaces of the walls 12 and I3 and take the shape of said walls. Adjacent their opposite projecting ends 21 and 28, these endsare flexed outwardly about the flanges 2| and 22, respectively, of the extension l1, and by reason of the stifiness of the strips and their somewhat resilient flexibility, the strips are retained in spread apart position, as well as shaped to the spirally curved contours of the walls 12 and 3- of' the holder I0.

It will be apparent that when the strips 24 and 25 are in position in the holder in, the abrasive means comprising the surfaces 26, beginning near the flexed ends of these strips, provide a wideflaring entrance, and continuing past the extension I! and between the walls I2. and I3, present spirally curved surfaces 29 and30, arranged in an acute -shaped formation, and which converge both laterally and longitudinally toward the end IQ of the holder Ill.

With this construction, the point of adrafting pencil, for example, may enter the acutely V- shaped trough between the spirally arranged abrasive surfaces; and then bedrawn through the trough. If it is desired to needle-pointthe pencil, the pencil may be twirled on its own axis by the fingers. during its passage through the troughyif a. chiselpoint isdesired, twirling ofthe pencil is: omitted. In each case, the spirally curved abrasive-surfaces simultaneously shape and gage the point, imparting aneedle point or'sharpedge toward the bottom of the trough, and tapering the point to a greater shapedthickness because of the divergent curved nature of theabrasive surfaces, so that a point ideally suitable for drafting purposes; is-imparted to the-lead. ihere is no tendency of the shaped point to break, either when it. is being sharpened or after it has been sharpened. Not only do the spirally curved and acutely V-shaped abrasive surfaces shape the point, but. it will be noted that the abrasive means themselves are shaped through the act of placing them within the holder, and: of course the abrasive strips are readily replaceable when desired; I

A somewhat different embodiment of the .in-- vention is illustrated in Figure 8. All parts are similar to those already described, except that in this embodiment walls 3land 32 are made somewhat wider than the walls [2 and; I3, and the extension 33 has. no function except to pro-,- vide a handle, or means-by which the device may be hung. upon a nail or the like. In this. construction the abrasive means.- take: the form ofstrips of emery cloth 34, one set of ends being clamped between the walls at the end 35 of the holder, and each strip34 extending along its'related. wall of the holder, terminating at the opposite end 36 of the holder where itis-cli-pped or held in place by aresilientfastener 31, preferably formed integrally with the related wall of the holder. In this construction, the walls 3| and 32 of the holder diverge laterally and longitudinally from the end 35 toward the end 36, and are curvedv laterally and longitudinally to provide the spiral curves heretofore referred to, and just before reaching the end 36, the walls 3| and 32, are flared as indicated at 38, to provide therelatively wide spirally curved entrance formation heretofore referred to in connection with Figures 1 through '7 and corresponding to the fiaredends 2.1 and 28 of the strips 24 and 25,

While I have illustrated and described the preferred form of construction for carrying my invention into effect, this is capable of variation and modification without departing from the spirit of the invention. I, therefore, do'notwish to be limited to the precise details of construction set forth, but desire to avail myself of such variations and modifications as come within the scope of the appended claims.

Having thus described my invention, what I claim asnew and desire to secure by Letters Patent is:

1. A device of the character described:v comprising a trough, a spreader extendingfrom'one endnofsaid trough symmetricaltherewith, a pair of pencil sharpeningabrasive sheets lining said trough. interiorly and together straddling said spreader in sprung. apart relation for the convenient entrance of a pencil sharpened between said sheets.

2. An abrasive'sheet holder comprising'a trough the. edges of which flare apart toward one end,

;. anupturned sheetspreader extending from saidone end said spreader serving to'spring apart abrasive sheets: disposed. in said' trough and hold same sprungagainst the flared apartedges of said trough.

3. An abrasive sheet holder having a trough in which abrasive sheets are retained opposing relation, and an upturned sheet spreader extend-- ing from one end of said trough symmetrical therewith said spreader serving to maintain I re sponsive ends of such sheets in sprung, apart relation, for the convenient entry, of work drawn between such sheets.

HUGH M. McCLURE.

REFERENCES CITED- The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 185,030 Hennaman Dec. 5; 1876*- 300,375 Knagge June 1'7, 1'88'4? 500,504 Moore June 27,1893 573,364 Simonds Dec. I5, 1896 705,322 Cortis' July 22,- 1902 1,522,958 Land Jan. 13', 1925' 2,238,340 Poe Apr. 15', 1941 

